1. Field of the Invention
The present invention relates generally to dial-up connection to internet service providers, and more particularly to an apparatus and method for accessing multiple internet service providers at low cost by using dial-up IP (internet protocol) service.
2. Description of the Related Art
Dial-up IP service allows subscribed user terminals to establish dial-up connections to internet service providers through a public switched telephone network. To provide this service, internet service providers are connected to the public switched telephone network through dial-up lines that are leased from the network provider and assigned phone numbers as in the case of most telephone subscribers. The total number of such leased lines is less than the number of subscribed users in order to establish a reasonable balance between operating cost and profit. However, communication traffic offered to the leased lines as well as to the public switched network will increase significantly when flat rate service is introduced for dial-up connections. In addition, since dial-up users are connected to internet service providers in a one-to-one correspondence, it is necessary for the internet service providers to install equipment in the public switched network that can communicate with the subscribers' modems with perfect compatibility. Further, due to communication protocols and transmission speeds of the installed equipment, the leased lines must be grouped according to such different implementation parameters and reassigned new phone numbers (i.e., pilot numbers) to maintain compatibility. The subscribers must be informed of the reassigned phone numbers to update their internet access number. Since different pilot numbers are used for different groups of leased lines, a split loss occurs in the utilization efficiency of transmission medium. This is particularly true of ADSL (asymmetric digital subscriber line) since the number of lines leased for this service is significantly limited.